fix test_root_dir() testcase to allow empty info dict
fix test_root_dir() testcase to allow empty info dict

pmitros/pyfs,pombreda/pyfilesystem,PyFilesystem/pyfilesystem,pmitros/pyfs,zopyx/pyfilesystem,flying-circus/pyfilesystem,rivenz/pyfilesystem,Konubinix/pyfilesystem,piranna/pyfilesystem